Hollow tyre of rotary furnaces and method of equalizing tyre temperatures

ABSTRACT

There are proposed a hollow tyre and a method of equalizing the temperature of this tyre by means of a heat carrier introduced into its inner space. Owing to the face that blades are arranged within the tyre space while the heat carrier is poured to a definite level, during the rotation of the tyre the heat carrier is distributed as a thin layer over the surface of the internal belt of the tyre and this results in intensive evaporation of the heat carrier on the internal belt and in condensation thereof on the external belt. As a result, the intensity of heat transfer is drastically increased.

United States Patent Dyskin et al.

[ Aug. 29, 1972 [54] HOLLOW TYRE OF ROTARY FURNACES AND METHOD OF EQUALIZING TYRE TEMPERATURES [72] Inventors: Ernest Matveevich Dyskin, ulitsa Ezhena Potie, 9, kv. 61.; Georgy Vladimirovich Raevsky, Pereulek Mechnikova, 3, kv. 6.; Semen Mikhailovich Biletsky, ulitsa Vemadskogo, 69a, kv. 9f; Eduard Jurievich Burmenko, ulitsa Entuziastov, 47, kv. 30.; Erikh Ruvimovich Grosman, ulitsa Artema, l0 kv. 62.; Abram Lamrevich Satanovsky, ulitsa Basseinaya, 5a, kv. 5.; Oleg Alexandrovich Kremnev, Bulvar Shevechenka, 51 kv. 52.; Viktor Yakovlevich Zhuravlenko, ulitsa Pimonenko, 20, kv. 10.; Boris Nikolaevich Protsyshin, ulitsa Dobry put, 4, kv. 1., all of Kiev, USSR.

[22] Filed: July 27, 1970 [21] Appl. No.: 58,613

[52] US. Cl ..266/24, 263/44 [51] Int. Cl ..F27b 7/38 [58] Field of Search ..266/24, 32, 36 H; 263/33 R, 263/33 A, 44

[56] References Cited UNITED STATES PATENTS 1,510,956 10/ 1944 Perkins ..263/44 Primary ExaminerGerald A. Dost Attorney-Waters, Roditi, Schwartz & Nissen [5 7] ABSTRACT There are proposed a hollow tyre and a method of equalizing the temperature of this tyre by means of a heat carrier introduced into its inner space. Owing to the face that blades are arranged within the tyre space while the heat carrier is poured to a definite level, during the rotation of the tyre the heat carrier is distributed as a thin layer over the surface of the internal belt of the tyre and this results in intensive evaporation of the heat carrier on the internal belt and in condensation thereof on the external belt. As a result, the intensity of heat transfer is drastically increased.

2 Claims, 3 Drawing Figures HOLLOW TYRE OFROTARY FURNACES AND METHOD OF EQUALIZING TYRE TEMPERATURES The present invention relates to hollow tyres of rotary roasting furnaces used in building material-making industry, metallurgy, Chemical industry, and other branches of industry and to a method of equalizing the temperature of the tyres.

Due to heating and expansion of the furnace body, thermal stresses and deformations appear in the tyres, which tend to break them and, at the same time, exert pressure on the furnace body in the place of location of the tyre.

This is quite dangerous in the process of operation of hollow tyres, especially those welded into the furnace body, and this fact has so far limited the field of application of such tyres.

To overcome the adverse effect of thermal stresses and deformations, it is sufficient to equalize the tyre temperature, namely between the internal and external belts thereof. This is attained by cooling the internal, more heated belt and simultaneously heating the external, less heated, belt and the tyre walls.

For this purpose, the tyre space is filled with a heat carrier which by means of convection provides for transfer of heat from the more heated internal belt to the less heated external belt (cf. Pat. No. 1,101,261 of the Federal Republic of Germany and USSR Authors Certificate No. 152,822 Cl. 80c, 1,401).

The disadvantage of such equalization of the tyre temperature consists in that it proceeds rather slowly.

Furthermore, this method requires high consumption of the heat carrier which, as a rule, is an expensive material.

An object of the invention is to eliminate the abovementioned disadvantages.

The principal object of the invention is to provide such a construction of the tyre and a method of equalizing the tyre temperature, which would ensure efficient transfer of heat from the internal belt to the external belt of the tyre at minimum consumption of the heat carrier.

This object is attained due to the fact that in the hollow tyre, the space of which is filled with a heat carrier for equalizing the tyre temperature, according to the invention, there are provided blades positioned within the space transversely to its cross section so that they transfer the heat carrier along the internal belt of the tyre.

It is most expedient to secure the blades on the side walls of the tyre with a gap relative to the internal belt of the tyre.

The blades may also be mounted without a gap relative to the internal belt of the tyre, but in this case they should be provided with perforations near the edge adjoining the internal belt of the tyre.

For a better transfer of the heat carrier the blades are preferably made as bilateral buckets secured on the side walls of the tyre with a gap relative to the internal and external belts of the tyre.

According to the invention, the method of equalizing the temperature of the hollow tyre by means of the heat carrier enclosed within the inner space of the tyre consists in that the tyre space is filled with a heat carrier to a depth equal or close to the width of the side wall of the tyre so that during the rotation of the tyre the heat carrier is distributed over the internal belt of the tyre as a thin layer.

Such a method provides for heat transfer from the more heated internal belt to the walls and external belt of the tyre not only due to convection heat exchange but also due to the phase transformations in the process of evaporation of the thin layer of the heat carrier continuously washing the internal belt of the tyre. In order to provide a dropwise shape of the condensate, the surface within the tyre space is covered with a layer of a compound which is not wetted by the heat carrier.

To intensify the evaporation of the heat carrier, a vacuum is produced within the tyre space.

The invention is further described by way of example with reference to the accompanying drawings, in which:

FIG. 1 is a sectional view of the furnace with a welded-in tyre, in the inner space of which there are provided blades in the form of bilateral buckets, this FIG. 1 also showing the distribution of a heat carrier within the space of the tyre;

FIG. 2 is a plan view, partly in section, of the same furnace and tyre;

FIG. 3 is another version of the blades provided with perforations along the edge adjoining the internal belt of the tyre.

As shown in the drawings, the tyre consists of a welded structure made of rolled stock or casting in the form of a ring 1 welded into the housing of the furnace 2.

The tyre includes an internal belt 3, an external belt 4 and side walls 5. Mounted inside the tyre space are blades in the form of bilateral buckets 6 disposed radially across the blade section.

The buckets 6 are welded to the side walls 5 with gaps 7 and 8 relative to the internal belt 3 and external belt 4, respectively. The blades can be made in the other way, as shown in Fig. 3. In this case the blades 9 also have a shapeof bilateral buckets welded to the side walls 5 without a gap relative to the internal belt 3 and the blades 9 are provided with perforations 10 made along the edge adjoining the internal belt 3.

The tyre space is filled with a heat carrier 11 to a depth equal to the height of the wall 5.

The inner surfaces of the external belt 4 and of the side walls 5 are preliminarily covered with a layer of a compound which is not wetted by the heat carrier 11. Vacuum pumps are used for producing a vacuum within the hermetically sealed space of the tyre filled with the heat carrier 1 1.

During the rotation of the tyre together with the furnace 2, the buckets 6 (or the blades 9).grab the heat carrier 11 occupying the lower portion of the tyre. Owing to the above-described construction and the mounting of the blades within the tyre space, the heat carrier 11 grabbed by the buckets 6(9) flows as a thin layer along the surface of the internal belt 3. This layer intensively removes the heat from the surface of the internal belt 3 and is freely evaporated into the hermetically sealed space of the tyre.

Due to the pre-established vacuum within the tyre space in the absence of a non-condensating gas (air), the produced pure vapors of the heat carrier have. a free access to the external belt 4 and side walls S-where they are intensively condensated, thus heating the said belt 4 and walls 5 due to the evolution of the heat of phase transformations absorbed during the evaporation. Thus, the heat exchange between the tyre members is effected not only due to the convection heat exchange, but also due to the phase transformations of the heat carrier 11.

Owing to the fact that the condensation surfaces are covered with a non-wetting layer, dropwise condensation will occur in the tyre space, which is known to be featured by very high heat-transfer coefficients of the order of 5,000 to 15,000 kcal/m .hr.deg. When the internal belt 3 is streamlined by a layer of an evaporating liquid, the heat transfer coefficient is within the range of 500 to 3,000 kcal/m .hr.deg.

Due to such low magnitudes of the external heat resistances on the surfaces of heat exchange within the tyre space and due to sufficiently low internal resistances of the steel parts of the tyre, walls 5 and external belt 4, the temperature in the tyre section is evenly distributed between all its members and becomes equal to the mean temperature of the vapor-liquid medium within the space of the construction.

The industrial tests of the experimental tyres of the abovedescribed construction mounted on cement furnaces have shown that the maximum temperature drop between the internal belt 2 and the external belt 4 does not exceed l 5C and this is not dangerous from the point of view of thermal stresses. The rate of uniform heating of the tyre of the above-described construction and its mean temperature are determined by the temperature of the gas flame inside the furnace, the conditions, therrnophysical properties and thickness of the inner refractory lining of the furnace and the intensity of the heat transfer on the external surfaces of the type.

The tyre of such a construction free from thermal stresses can be welded into the furnace body and is rated only for mechanical loads.

The similar construction and the method of equalizing temperatures can be used for stiffening rings of the body of a rotary roasting furnace.

We claim:

1. A method of equalizing the temperature of a tyre of a rotary furnace by means of a heat carrier placed into said tyre, consisting in that the inner space of the tyre is filled with a heat carrier to a depth equal or close to the width of the side wall of the tyre so that during the rotation of said tyre said heat carrier is distributed by the built-in blades as a thin layer over the internal belt of said tyre, and in which the inner surfaces of said side walls and said external belt are covered with a compound which is not wetted by said heat carrier.

2. A method as claimed in claim 1, in which a vacuum is produced within said space of said tyre filled with said heat carrier. 

1. A method of equalizing the temperature of a tire of a rotary furnace by means of a heat carrier placed into said tire, consisting in that the inner space of the tire is filled with a heat carrier to a depth equal or close to the width of the side wall of the tire so that during the rotation of said tire said heat carrier is distributed by the built-in blades as a thin layer over the internal belt of said tire, and in which the inner surfaces of said side walls and said external belt are covered with a compound which is not wetted by said heat carrier.
 2. A method as claimed in claim 1, in which a vacuum is produced within said space of said tire filled with said heat carrier. 